The manufacture of imitation cheese products of the type to which the present invention relates is known. Such manufacture offers a number of advantages. For instance, the use of acid-set avoids the need for maintaining acid-producing micro-organisms conventionally employed in the cheese-making process. Also avoided are the formations of whey as a by-product and the accompanying need for separation and disposal of the same.
One such acid-set cheese product is disclosed in a prior Bell et al U.S. Pat. No. 3,922,374. In this patent, the cheese ingredients are said to be a fat having a Wiley melting point between about 90.degree. and 110.degree. F, the fat being about 12 to 35% of the cheese product; a calcium caseinate, sodium caseinate, or a combination of such caeinates in an amount equal to about 15 to 33% of the cheese product; up to about 5% ungelantinized flour; and about 0.5 to 1.8% adipic, lactic, citric, or malic acid, or combinations of such acids; and water, the cheese product having a pH of about 4.8 to 5.7 and including appropriate coloring and flavoring materials.
Traditionally, cheese is made on a batch-type basis, for instance in producing cultured products. Such products must be allowed to stand, and the process thus is not amenable to continuous operation and automation techniques. Reference is made to this problem in a prior Little U.S. Pat. No. 3,378,375, column 2 of the patent.
Even imitation and filled cheeses insofar as known to Applicants continue to be made using batch-type techniques. In said prior U.S. Pat. No. 3,922,374, the mixing is carried out in what is described as a high shear mixer sold by Littleford Brothers, Inc., Cincinnati, Ohio, U.S.A. This batch-type mixer includes a steam-jacketed, cylindrical chamber which has a filling door at the top and a discharge door at the bottom. The mixer is filled prior to processing and emptied when processing is completed. It is described as having a series of rotating arms the outer ends of which have a plow-shaped impeller or mixing element fitting the inner surface of the chamber and projecting material away from the inner surface, hurling the same towards the axis of the chamber. Protruding from the lower wall of the vessel and into the chamber are a series of high-speed blending choppers which are spaced between the mixing arms. The choppers rotate at high speed to break up agglomerates.
It is a characteristic of the process of this patent that a particular sequence of addition of the cheese formulation ingredients is used, necessitating the use of a batch mixing apparatus or process. In particular, the process of the patent employs what is called in-situ forming of caseinate, described as the addition of casein to the mixing chamber, as hydrochloric casein, followed by addition of a base, such as calcium hydroxide, reactable with the casein during the mixing operation. It is pointed out in the patent that the in-situ forming is necessary towards obtaining an acceptable product, particularly for certain uses.
It is believed that a principal problem with the manufacture of imitation cheeses by the process of acid-setting, heretofore requiring a batch-mixing operation, is that the addition of an edible acid such as lactic acid to a casein-containing mixture causes premature agglomeration resulting in the production of an uneven curd of varying quality. In accordance with the above-mentioned Little U.S. Pat. No. 3,378,375, it is surmised that the acid overacidifies portions of the casein-containing product causing premature precipitation of these portions while other portions which are the last to be acidified form a large, hard, coarse curd. By comparison, when bacteria cultures are employed, the acid is formed slowly, uniformly and in situ so that the acidity of the milk product lowers slowly and uniformly. Even when concentrated acids are added slowly and under proper conditions of temperature and agitation, a consistently uniform product is still difficult to obtain. Also, this requires additional time, detracting from the attractiveness of the procedure. Also reference can be had to Little U.S. Pat. No. 3,792,171 on this same subject.